Cute little cartoon monsters in a vintage classroom scene

a nice group of cute and adorable little monsters, one of them is small and furry, orange in color with big eyes and no mouth, another tall and very thin one is a thin stick with big eyes and eyebrows, another little chubby one with a smile from ear to ear with many teeth, all his teeth can be seen and they are tightly packed. They are in a classroom from the 50s. On the right side there is a window through which the light comes in.